MerlinSEO

What MerlinSEO does

MerlinSEO is a Windows app for people who run their own websites. It crawls your site, checks every page against more than 80 search rules, and turns what it finds into a task list ordered by quick wins. Every finding shows its evidence: the page, the element and the measured value. When you fix something, MerlinSEO checks it again and closes the task only when the problem is gone.

• Site audit: broken links and redirects, titles and descriptions, headings, canonical tags, robots rules, sitemaps, structured data, mobile, security, social previews and accessibility basics.
• Tasks that re-check themselves: priority by impact and effort, a board view, exports to CSV, Markdown or HTML, and a developer handoff with fix snippets.
• Search engines kept current: when pages are added, changed or removed, MerlinSEO tells search engines through their official channels: IndexNow, Bing Webmaster Tools and Google Search Console. It sends only what changed, never the whole site again.
• Monitoring: once you turn on a site's schedule, it checks uptime, robots.txt, sitemaps and the security certificate, and alerts you in the notification area when something breaks.
• A command line for scripts and build pipelines, and a portable copy that runs from a folder.

Google Search Console and your data

Connecting Google is optional. If you sign in with Google, MerlinSEO asks for permission to use Search Console for the sites you own. It uses that permission only to:

• read search performance (queries, pages, clicks, impressions and position);
• read URL Inspection results, such as whether a page is indexed;
• list your sitemaps and submit a sitemap when it is new or has changed.

That data goes from Google straight to your PC and is stored there. It is never sent to Virtual Merlin or to anyone else. You can disconnect Google in the app at any time, or remove MerlinSEO's access in your Google account settings. Details are in our privacy policy.

Price

Free. No trial, subscription, account or ads. MerlinSEO needs no AI key; any future AI suggestions will be optional and use your own key.

The MerlinSEO crawler

If you found MerlinSEO in your server logs, this section explains what it is. Someone who uses MerlinSEO crawled your site, usually to audit a site they own.

How it identifies itself

Every request carries this User-Agent, with the app's version number:

MerlinSEO/1.0.0 (+https://www.vmerlin.com/merlinseo)

It never pretends to be Googlebot or another search engine. When its optional JavaScript rendering is on, pages are loaded in the Microsoft Edge WebView2 engine, and the browser's User-Agent ends with the same MerlinSEO/… text.

How it behaves

• It reads robots.txt first and obeys the rules for MerlinSEO, or for * when there is no MerlinSEO group.
• By default it sends at most two requests at a time, with a pause after each one.
• It slows down when a server answers 429 or 503, honors Retry-After, and honors Crawl-delay up to 30 seconds.
• It runs on the computer of the person using the app, not from a central service, so requests come from that person's own internet connection.
• It is meant for sites the user owns. It does not fill in forms, log in or click buttons.

How to block it

Add this to your robots.txt to keep MerlinSEO out of your whole site:

User-agent: MerlinSEO
Disallow: /

Or block only part of the site, for example Disallow: /private/.

Questions or problems

If MerlinSEO is causing trouble on a site you run, tell us and include a few lines from your access log. We read every message.